1. Field of the Invention
This invention pertains to refrigeration system dehydrators and more specifically in one aspect thereof to a dehydrator employing water-absorbing polymers.
2. Description of the Prior Art
Refrigeration systems in buildings, residences, automobiles and the like generally employ a number of components that cycle a refrigerant through a closed loop of vapor and liquid phases. Typically, freon, as an example of a suitable refrigerant, changes from a gas condition to a liquid condition and back to a vapor condition as it progresses through a refrigeration cycle. Although the refrigerant is primarily freon, it is well-known that it is advantageous for the refrigerant also to include some lubricating oil to maintain the smooth running operation of the mechanical components and so as to minimize the onset of rust. Further, as the refrigerant cycles through its phases there is an inherent accumulation of water condensate or water vapor. The presence of a minute quantity of water is not particular disadvantageous, but when there is water build up, the efficiency of the refrigeration condition is adversely affected and the presence of water can even cause rust or other damage to the operating components. It is known, for example, that water in the presence of most refrigerants forms an acid that deteriorates the coils and other components of a refrigeration system.
In order to prevent the build up of water in a refrigeration system, a dehydrator is included, normally located in the loop of a simple refrigeration system between the evaporator and the compressor. A typical dehydrator includes a housing in which gas expanded refrigerant is directed as a vapor. Inside the housing is a dessicant that absorbs and thereby drys or removes the water, or at least excess water, from the vapor. In addition to removing water, the usual dehydrator also includes one or more filters for removing solids particulates that might inadvertently be introduced.
Dessicants currently in use when first put into service have proven to be satisfactory. That is, when drying is occurring when the dessicant is fresh, refrigeration of the entire system operates at a high level of efficiency and the parts operate without undue wear. However, the lubricating oil will, in time, begin to coat the dessicant, causing water removal to become less and less efficient until such time as the dehydrator must be replaced.
Dehydrator replacement is not difficult, but it is somewhat expensive. Typically, the system is shut down, the input and output connections to the housing of the dehydrator are disconnected and the dehydrator is replaced. Usually, there is nothing wrong or wornout about the housing of the replaced dehydrator, only the dessicant has been oil-contaminated or has reached its level of water absorption. Nevertheless, the entire unit is replaced.
Therefore, it is a feature of the present invention to provide an improved substance for absorbing water from the coolant or refrigerant of a refrigeration system that remains efficient even when coated with oil.
It is another feature of the present invention to provide an improved dehydrator for a refrigeration system having a replaceable container of water-absorbing or water-encapsulating polymers that provide both efficient operation and is easy and inexpensive to replace.